Tantalum nitride-p-silicon high-voltage Schottky diodes

Rectifying contacts between TaN and p-silicon with very high reverse breakdown voltage (V_BR >700 V) without using any guard ring have been realized. Barrier heights of TaN to both p-type silicon and n-type silicon have been measured at 0.68 and 0.48 eV, respectively. The breakdown voltage V_BR of TaN to p-silicon diodes, as deposited, is ~400 V and decreases to less than 200 V after annealing in hydrogen at 450°C for 30 min. On the other hand, annealing in a nitrogen ambient at 450°C for 30 min. increases the V_BR of these diodes to more than 700 V. An explanation for the difference in V_BR is sought in terms of the structural/chemical changes introduced at the interface by the annealing process. The high forward drop of TaN to p-silicon diodes (>1 V at 10 mA) results from the high substrate resistance and the probe contact resistance, and it is being optimized